CN101616995A - Solvent-free organopolysiloxane composition forming cured release coating and substrate in sheet form with cured release coating - Google Patents

Abstract

Solvent-free organopolysiloxane composition for forming a cured release coating comprising: (A) 100 parts by weight of a siloxane unit having a branched structure and comprising (i) represented by the chemical formula SiO _4/2 , (ii) an organopolysiloxane fluid having a siloxane unit represented by the general formula R ₂ SiO _2/2 , and (iii) a siloxane unit represented by the general formula R ^a R ₂ SiO _1/2 ; (B) 0.5-15 parts by weight of an average structural formula of R ^a R ^c ₂ SiO (R ^b R ^c SiO _2/2 ) _n1 (R ^c ₂ SiO _2/2 ) _n2 SiR ^c ₂ R ^a diorganopolysiloxane (C) a predetermined amount of organohydrogenpolysiloxane; and (D) a hydrosilylation reaction catalyst. Furthermore, a substrate in the form of a sheet having a cured coating obtained from this solvent-free cured release coating-forming organopolysiloxane composition.

Description

Solvent-free organopolysiloxane composition forming cured release coating and substrate in sheet form with cured release coating

technical field

[0001] The present invention relates to solvent-free organopolysiloxane compositions that form cured release coatings that can be applied to substrates in sheet form such as paper, polyolefin-laminated paper, thermoplastic resin films, A cured release coating is formed on the surface of metal foil or the like; excellent peeling performance against sticky substances can be provided; and a treated surface with smooth sliding properties can be provided. The invention also relates to a substrate in the form of a sheet with a cured release coating obtained by curing the composition.

Background technique

Addition reaction curable organopolysiloxane by dissolving alkenyl functional diorganopolysiloxane gum, organohydrogenpolysiloxane and hydrosilylation reaction catalyst in an organic solvent such as toluene Solution-type organopolysiloxane compositions prepared from oxane compositions are well known and are generally used on the surface of substrates in sheet form such as various papers, laminated papers, synthetic films, metal foils, etc. An organopolysiloxane composition for use in forming a cured coating exhibiting release properties relative to sticky substances.

[0003] Emulsion-type organopolysiloxane compositions provided by emulsification addition reaction curable organopolysiloxane compositions in water have been introduced in JP47-032072A (Patent Reference 1) and JP53-003979B (Patent Reference 2). A solvent-free organopolysiloxane composition containing only a low viscosity addition reaction-curable organopolysiloxane composition that is liquid at ambient temperature as a solution as described above type of addition reaction-curable organopolysiloxane composition, and has come into practical use. Based on safety and environmental considerations, a solvent-free organopolysiloxane composition for forming a cured release coating has been demanded in a wide range of applications in recent years as a solution-type alternative, and in response, in JP2004-307691A An organopolysiloxane composition forming such a solvent-free cured release coating is introduced in (Patent Reference 3).

[0004] However, since the vinyl-functional diorganopolysiloxane used as the base ingredient in the existing solvent-free organopolysiloxane composition for forming a cured release coating has about 50- The low viscosity of 1000 cSt, therefore, although these compositions show good coatability, they give cured coatings with poor sliding properties, with the consequence that their applications are limited. Therefore, when a solvent-free cured release coating-forming organopolysiloxane composition having this low-viscosity vinyl-functional diorganopolysiloxane as its base is used as a release film for kraft tape When the adhesive is used, the resulting cured coating exhibits poor sliding properties, and a method of pasting kraft paper tape on, for example, cardboard cannot be performed smoothly; and the pressure-sensitive adhesive cannot be completely bonded and peeling may occur. When a cured coating is formed on paper, laminated paper, or plastic film, the cured coating again exhibits poor slipperiness, which causes problems such as damage to the tape and failure of the tape to rotate smoothly. From a process point of view, This may be the cause of the quadratic problem.

[0005] Furthermore, when a solvent-free addition reaction-curable organopolysiloxane composition having such a low-viscosity vinyl-functional diorganopolysiloxane as its base component is applied to paper or plastic When forming a cured coating on a paper or plastic film, the poor sliding properties of the cured coating cause, for example, damage to the cured coating when a release paper or a release film is produced, and when it is subsequently coated with an adhesive substance, uneven Peeling characteristics, and problems such as the inability to smoothly rewind the release paper or release film, are caused by the cured coating coming into contact with metal or plastic foil or plastic rolls prior to the release paper or release film being rewound of.

[0006] In order to improve the sliding properties of the cured coating, JP61-159480A (Patent Reference 4) proposes a solvent-free addition reaction curable organopolysiloxane composition for release paper applications, wherein the base component is 1) a linear organopolysiloxane having a viscosity of 50-100,000 cps and a vinyl content of 0.5-10.0 mol%, and 2) a linear organopolysiloxane having a low vinyl content and a viscosity of at least 100,000 cps oxane. JP61-264052A (Patent Reference 5) proposes a solvent-free addition reaction curable silicone composition for release paper applications, which has a viscosity of 50-10,000 cps and has a viscosity of 50-10,000 cps and vinyl A linear organopolysiloxane having a group content of 0.5-10.0% of all organic groups, and a substantially linear organopolysiloxane having a viscosity of at least 100,000 cps and having a hydroxyl group at a molecular end are used as base components. However, since these compositions contain a large amount of linear diorganopolysiloxane having a viscosity of 50 to 10,000 cps, cured coatings prepared therefrom cannot provide fully satisfactory slip properties.

[0007] On the other hand, in JP55-110155A (Patent Reference 6) and JP2005-255928A (Patent Reference 7), a solventless addition reaction curing type organopolysiloxane for forming a cured coating is proposed Alkane composition (it contains R ₃ SiO _1/2 unit (= M unit), R ₂ SiO _2/2 unit (= D unit) or RSiO _3/2 unit (= T unit) and SiO _4/2 unit ( = Q units) and having at least two alkenyl groups per molecule) and a solvent-free addition reaction curing type organopolysiloxane composition forming a cured release coating (which has R ₃ organopolysiloxane resin of SiO _1/2 unit (=M unit) and SiO _4/2 unit (=Q unit) as its base component). In JP2001-064390A (Patent Reference 8) and EP1070734A2 (Patent Reference 9), a hydrosilylation reaction-curable siloxane-based anti-sticking coating composition is also proposed, wherein the basic component is the aforementioned Q unit, a specific amount of D Alkenyl-functional branched organopolysiloxanes of M units and M units. These compositions and especially the compositions in Patent Reference 8 and Patent Reference 9 exhibit excellent curability, and coatings obtained by curing them exhibit excellent adhesion to substrates, excellent residual adhesion etc.; however, this cured coating has a large coefficient of friction and is therefore not entirely satisfactory from the viewpoint of sliding properties.

[0008] JP2001-064390A (Patent Reference 8) and EP1070734A2 (Patent Reference 9) teach that silicone-based release coating compositions may additionally incorporate alkenylated polydiorganosiloxanes such as ii ) alkenyldialkylsilyl-terminated polydiorganosiloxane and preferably dimethylvinylsilyl-terminated polydimethylsiloxane and/or dimethylhexenylsilyl End-capped polydimethylsiloxane, wherein preferably alkenyl-functional branched organopolysiloxane is 25-85% by weight, and the balance is ii) alkenyldialkylsilyl-terminated polydimethicone Organosiloxanes. However, there is no awareness of the decrease in the coefficient of friction of the cured coating, and an increase in its slidability, nor is there any mention of means for reducing the coefficient of friction of the cured coating and increasing its slidability.

Summary of the invention

[0009] In order to solve the problems described above, the present invention has been proposed, and the object of the present invention is to introduce a solvent-free organopolysiloxane composition forming a cured release coating which, when cured, forms a The substrates exhibit good adhesion with good residual adhesion and coatings with improved release properties to sticky substances and improved slip. Another object of the present invention is to provide a substrate in sheet form with a cured coating which exhibits good adhesion to the substrate with good residual adhesion and improved release properties for sticky substances and Has improved sliding properties.

[0010] The present invention relates to a solvent-free cured release coating-forming organopolysiloxane composition comprising:

(A) 100 parts of an organopolysiloxane fluid having a branched structure and comprising the following units:

(i) a siloxane unit represented by the formula SiO _4/2 ,

(ii) a siloxane unit represented by the general formula R2SiO2 _{/ 2} , and

(iii) a siloxane unit represented by the general formula R ^a R ₂ SiO _1/2 ;

(B) 0.5-15 parts of an average structural formula of a diorganopolysiloxane as follows:

R ^a R ^c ₂ SiO(R ^b R ^c SiO _2/2 ) _n1 (R ^c ₂ SiO _2/2 ) _n2 SiR ^c ₂ R ^a ;

(C) a predetermined amount of organohydrogenpolysiloxane; and

(D) Hydrosilylation reaction catalyst.

The present invention also relates to substrates in sheet form having a cured coating obtained from this solvent-free cured release coating-forming organopolysiloxane composition.

invention disclosure

[0011] The above-described objects can be achieved as follows.

{1} A solvent-free cured release coating-forming organopolysiloxane composition characterized by comprising:

(A) 100 parts by weight have a branched structure and a viscosity of 10-1,000 mPa.s at 25°C, comprising siloxane units (i)-(iii) described below, and having a plurality of siloxane units The linear part of (ii), and the organopolysiloxane fluid containing the branch point of the siloxane unit (i), wherein the end of the linear part is terminated with the siloxane unit (iii)

(i) Siloxane units represented by the chemical formula SiO _4/2 : 1 or more

(ii) Siloxane units represented by the general formula R ₂ SiO _2/2 : 15-995

(iii) A siloxane unit represented by the general formula R ^a R ₂ SiO _1/2

(In these formulas, R ^a is selected from alkyl having 1-8 carbon atoms, alkenyl having 2-8 carbon atoms, phenyl, alkoxy having 1-8 carbon atoms, and A group of hydroxyl, and R is selected from an alkyl group with 1-8 carbon atoms, an alkenyl group with 2-8 carbon atoms, and a phenyl group, wherein at least one of R ^and R in the molecule Three are alkenyl groups having 2-8 carbon atoms, and at least 50% of the total number of ^R and R in the molecule are alkyl groups having 1-8 carbon atoms);

(B) 0.5-15 parts by weight of a diorganopolysiloxane represented by the average structural formula (1) and having a viscosity of at least 100,000 mPa.s at 25°C:

R ^a R ^c ₂ SiO(R ^b R ^c SiO _2/2 ) _n1 (R ^c ₂ SiO _2/2 ) _n2 SiR ^c ₂ R ^a (1)

(Wherein R ^a is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, a phenyl group, an alkoxy group having 1-8 carbon atoms, and a hydroxyl group ; R ^b is an alkenyl group having 2-8 carbon atoms; R ^c is an alkyl or phenyl group having 1-8 carbon atoms; 0-0.1 of the total number of R ^a , R ^b and R ^c in the molecule % is an alkenyl group having 2 to 8 carbon atoms; at least 50% of the total number of R ^a , R ^b and R ^c in the molecule is an alkyl group having 1 to 8 carbon atoms; n1 is a value of at least 0 number; n2 is a number having a value of at least 1; and n1+n2 is a number providing a viscosity of this component at 25° C. of at least 100,000 mPa.s);

(C) an organohydrogenpolysiloxane having a viscosity of 1 to 1000 mPa.s at 25° C. and having at least two silicon-bonded hydrogen atoms per molecule, wherein the silicon-bonded organic group has 1 - an alkyl group of 8 carbon atoms, or a phenyl group, in an amount sufficient to provide a ratio of 0.8:1 to 5:1 of silicon-bonded hydrogen atoms to component (A ) and (B) the molar ratio of internal alkenyl groups; and

(D) A catalytic amount of a hydrosilylation catalyst.

{2} The solventless cured release coating-forming organopolysiloxane composition according to {1}, characterized in that component (A) is a siloxane having a branched structure and containing the following average siloxane Organopolysiloxane represented by the unit formula (2):

(R ^a R ₂ SiO _1/2 ) ₄ (R ₂ SiO _2/2 ) ^m (SiO _4/2 ) (2)

(Wherein R ^a is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, a phenyl group, an alkoxy group having 1-8 carbon atoms, and a hydroxyl group R is selected from an alkyl group with 1-8 carbon atoms, an alkenyl group with 2-8 carbon atoms, and a phenyl group; at least 3 of R ^and R in the molecule have 2 - an alkenyl group with 8 carbon atoms; at least 50% of the total number of R ^a and R in the molecule is an alkyl group with c8 carbon atoms; and m = 15-995).

{3} The solventless cured release coating-forming organopolysiloxane composition according to {2}, characterized in that component (A) is a siloxane having a branched structure and containing the following average siloxane Organopolysiloxane represented by unit formula (3):

[(R ^b R ^c ₂ SiO _1/2 ) _n (R ^d R ^c ₂ SiO _1/2 ) _1-n ] ₄ (R ^b R ^c SiO _2/2 ) _m1 (R ^c ₂ SiO _2/2 ) _m2 (SiO _4/2 )(3)

(wherein R ^b is an alkenyl group having 2-8 carbon atoms; R ^c is an alkyl group or phenyl group having 1-8 carbon atoms; R ^d is selected from an alkyl group having 1-8 carbon atoms , an alkoxy group having 1 to 8 carbon atoms, and a hydroxyl group; in the molecule at least three R ^b ; in the molecule at least 50% of the total number of R ^b , R ^c and R ^d are an alkyl group of 1-8 carbon atoms; n is 0 or 1; m1 is a number having a value of at least 0; m2 is a number having a value of at least 1; and m1+m2=15-995).

{4} The solventless cured release coating-forming organopolysiloxane composition according to {2}, characterized in that, in the average siloxane unit formula (2), R is a methyl group, and R ^a is a vinyl group; in the average structural formula (1), R ^a is a vinyl group, a methyl group or a hydroxyl group, R ^b is a vinyl group, and R ^c is a methyl group; and the alkyl group in the component (C) is methyl.

{5} The solventless cured release coating-forming organopolysiloxane composition according to {3}, characterized in that, in the average siloxane unit formula (3), R ^b is a vinyl group, R ^c is methyl, and n=1; in the average structural formula (1), R ^a is vinyl, methyl or hydroxyl, R ^b is vinyl, and R ^c is methyl; in component (C) Alkyl is methyl.

{6} The solventless cured release coating-forming organopolysiloxane composition according to any one of {1}-{3}, characterized in that the composition as a whole has a viscosity at 25°C 50-2000mPa.s.

{6-1} The solventless cured release coating-forming organopolysiloxane composition according to {4} or {5}, characterized in that the composition as a whole has a viscosity at 25° C. of 50-2000mPa.s.

{7} The solventless cured release coating-forming organopolysiloxane composition according to any one of {1}-{3}, characterized in that it additionally contains 0.001-5 parts by weight of (E) hydrogenated Inhibitor of the silanization reaction, and it does not cure at ambient temperature but cures with the application of heat.

{7-1} The solventless cured release coating-forming organopolysiloxane composition according to {6}, characterized in that it additionally contains 0.001 to 5 parts by weight of (E) an inhibitor of hydrosilylation reaction agent, and it does not cure at ambient temperature but cures with the application of heat.

[0012]

{8} The solvent-free, cured release coating-forming organopolysiloxane composition according to any one of {1}-{7} in the form of a film obtained by curing a substrate in the form of a sheet Sheet form substrate of cured release coating.

{8-1} A cured anti-adhesive coating obtained by curing the solvent-free cured release coating-forming organopolysiloxane composition according to {7-1} in the form of a film on a substrate in the form of a sheet Adhesive coated substrates in sheet form.

{9} The substrate in sheet form with a cured release coating according to {8} or {8-1}, characterized in that the substrate in sheet form is cellophane, clay-coated paper, polyolefin laminate paper, thermoplastic resin film or metal foil.

[0013] The solventless cured release coating-forming organopolysiloxane compositions of the present invention, when cured on a sheet-form substrate, form a coating that exhibits Excellent adhesion and has excellent residual adhesion, and also exhibits improved peel performance for sticky substances and has improved slip.

The substrates of the present invention in sheet form with cured release coatings exhibit good adhesion to substrates and have good residual adhesion and also show improved release properties and have improved release properties to sticky substances. sliding.

Best Mode for Carrying Out the Invention

[0014] The solventless cured release coating-forming organopolysiloxane composition of the present invention is characterized in comprising:

(A) 100 parts by weight have a branched structure and a viscosity of 10-1,000 mPa.s at 25°C, comprising siloxane units (i)-(iii) described below, and having a plurality of siloxane units The linear part of (ii), and the organopolysiloxane fluid containing the branch point of the siloxane unit (i), wherein the end of the linear part is terminated with the siloxane unit (iii)

(i) Siloxane units represented by the chemical formula SiO _4/2 : 1 or more

(ii) Siloxane units represented by the general formula R ₂ SiO _2/2 : 15-995

(iii) A siloxane unit represented by the general formula R ^a R ₂ SiO _1/2

(In these general formulas, R ^a is selected from alkyl having 1-8 carbon atoms, alkenyl having 2-8 carbon atoms, phenyl, alkoxy having 1-8 carbon atoms, and a hydroxyl group, and R is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, and a phenyl group, wherein R ^and R in the molecule At least three are alkenyl groups having 2-8 carbon atoms, and at least 50% of the total number of R ^and R in the molecule are alkyl groups having 1-8 carbon atoms);

(B) 0.5-15 parts by weight of a diorganopolysiloxane represented by the average structural formula (1) and having a viscosity of at least 100,000 mPa.s at 25°C:

R ^a R ^c ₂ SiO(R ^b R ^c SiO _2/2 ) _n1 (R ^c ₂ SiO _2/2 ) _n2 SiR ^c ₂ R ^a (1)

(Wherein R ^a is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, a phenyl group, an alkoxy group having 1-8 carbon atoms, and a hydroxyl group ; R ^b is an alkenyl group having 2-8 carbon atoms; R ^c is an alkyl group or phenyl group having 1-8 carbon atoms; 0- of the total number of R ^a , R ^b and R ^c in the molecule 0.1% is an alkenyl group having 2-8 carbon atoms; at least 50% of the total number of Ra ^{, Rb} and ^Rc in the molecule is an alkyl group having 1-8 carbon atoms; n1 is a value of at least 0 n2 is a number having a value of at least 1; and n1+n2 is a number providing a viscosity of this component at 25°C of at least 100,000 mPa.s);

(C) an organohydrogenpolysiloxane having a viscosity of 1 to 1000 mPa.s at 25° C. and having at least two silicon-bonded hydrogen atoms per molecule, wherein the silicon-bonded organic group has 1 - an alkyl group of 8 carbon atoms, or a phenyl group, in an amount sufficient to provide a ratio of 0.8:1 to 5:1 of silicon-bonded hydrogen atoms to component (A ) and (B) the molar ratio of internal alkenyl groups; and

(D) A catalytic amount of a hydrosilylation catalyst.

[0015] Component (A) has a branched structure and a viscosity of 10-1,000mPa.s at 25°C, comprising siloxane units (i)-(iii) described below, and having a plurality of silicon A linear portion of oxane units (ii), and an organopolysiloxane fluid containing branch points of siloxane units (i), wherein the end of said linear portion is capped with siloxane units (iii) end

(i) Siloxane units represented by the chemical formula SiO _4/2 : 1 or more

(ii) Siloxane units represented by the general formula R ₂ SiO _2/2 : 15-995

(iii) A siloxane unit represented by the general formula R ^a R ₂ SiO _1/2

(In these general formulas, R ^a is selected from alkyl having 1-8 carbon atoms, alkenyl having 2-8 carbon atoms, phenyl, alkoxy having 1-8 carbon atoms, and a hydroxyl group, and R is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, and a phenyl group, wherein R ^and R in the molecule At least three are alkenyl groups having 2-8 carbon atoms, and at least 50% of the total number of R ^a and R in the molecule are alkyl groups having 1-8 carbon atoms).

In this specification, the siloxane unit (i) represented by the chemical formula SiO _4/2 is abbreviated as Q unit in some cases; the siloxane unit (ii) represented by the general formula R ₂ SiO _2/2 is in some cases hereinafter abbreviated as D unit; and the siloxane unit (iii) represented by the general formula R ^a R ₂ SiO _1/2 is abbreviated as M unit in some cases.

In the component (A) containing one siloxane unit (i) represented by chemical formula SiO _4/2 , SiO _4/2 acts as a branch point, and contains represented by general formula R ₂ SiO _2/2 Linear chains of siloxane units (ii) extend therefrom in 4 directions, and siloxane units (iii) represented by the general formula R ^a R ₂ SiO _1/2 are bonded to end groups of these linear chains. Therefore, in component (A), the number of siloxane units (iii) represented by the general formula R ^a R ₂ SiO _1/2 is equal to the number of linear chains.

An organopolysiloxane having such a branched structure can be represented by the following average siloxane unit formula (4):

[(R ^a R ₂ SiO _1/2 )(R ₂ SiO _2/2 ) _m/4 ] ₄ (SiO _4/2 ) (4)

In fact, since the R ^a R ₂ SiO _1/2 units are directly bonded to the SiO _4/2 units, it is also possible to mix the siloxane units represented by the general formula R ₂ SiO _2/2 ( Molecules in which the polymer chains of ii) extend only in three directions or in two directions. An organopolysiloxane having such a branched structure can be represented by the following average siloxane unit formula (2).

(R ^a R ₂ SiO _1/2 ) ₄ (R ₂ SiO _2/2 ) _m (SiO _4/2 ) (2)

The number of siloxane units (i) represented by the chemical formula SiO _4/2 is one or more. For example, a number of up to 4 is possible, but 1 is preferred from the viewpoint of the characteristics of the organopolysiloxane.

In aforementioned general formula, ^R is selected from the alkyl group with 1-8 carbon atoms, the alkenyl group with 2-8 carbon atoms, phenyl, the alkoxy group with 1-8 carbon atoms A group, and a hydroxyl group; and R is a group selected from an alkyl group with 1-8 carbon atoms, an alkenyl group with 2-8 carbon atoms, and a group in a phenyl group; wherein in the molecule R At least 3 of ^a and R are alkenyl groups with 2-8 carbon atoms; in the molecule R ^a and at least 50% of the total number of R are alkyl groups with 1-8 carbon atoms; and m=15- 995.

In the aforementioned general formula (4) or the aforementioned general formula (2), each R ^a may be the same or different, and within the same molecule, each R may be the same or different.

[0019] Typical examples of such an alkyl group having 1 to 8 carbon atoms are methyl, ethyl, propyl and the like, among which methyl is preferred. Typical examples of the alkenyl group having 2 to 8 carbon atoms are vinyl, allyl, hexenyl and the like, among which vinyl is preferred. The alkoxy group having 1 to 8 carbon atoms may be methoxy, ethoxy and the like.

The R ^a R ₂ SiO _1/2 unit may, for example, be a Vi(Me ₂ )SiO _1/2 unit, a He(Me) ₂ SiO _1/2 unit, a (Me) ₃ SiO _1/2 unit, a ViMePhSiO _1/2 unit, and (HO)(Me) ₂ SiO _1/2 units (where Vi represents vinyl, He represents hexenyl, Me represents methyl, and Ph represents phenyl; this also applies below). Combinations of these units (eg Vi(Me ₂ )SiO _1/2 units and (Me) ₃ SiO _1/2 units) are also possible within the same molecule.

The R ₂ SiO _2/2 unit may, for example, be a (Me) ₂ SiO _2/2 unit, a ViMeSiO _2/2 unit or a MePhSiO _2/2 unit. Combinations of these units (eg (Me) ₂ SiO _2/2 units and ViMeSiO _2/2 units) are also possible within the same molecule.

In order to achieve excellent adhesion to substrates in the form of sheets, in the average siloxane unit formula (4) and the average siloxane unit formula (2), the R ^a R ₂ SiO _1/2 unit preferably contains 2- Alkenyl groups of 8 carbon atoms, for example Vi(Me) ₂ SiO _1/2 units, He(Me) ₂ SiO _1/2 units and ViMePhSiO _1/2 units.

[0020] This organopolysiloxane having a branched structure can more particularly be represented by the following average siloxane unit formula (5):

[(R ^b R ^c ₂ SiO _1/2 ) _n (R ^d R ^c ₂ SiO _1/2 ) _1-n (R ^b R ^c SiO _2/2 ) _m1/4 (R ^c ₂ SiO _2/2 ) _{m2 /4} ] ₄ (SiO _4/2 )(5)

and are additionally represented by the following average siloxane unit formula (3):

[(R ^b R ^c ₂ SiO _1/2 ) _n (R ^d R ^c ₂ SiO _1/2 ) _1-n ] ₄ (R ^b R ^c SiO _2/2 ) _m1 (R ^c ₂ SiO _2/2 ) _m2 (SiO _4/2 ) (3)

In the aforementioned general formula, R ^b is an alkenyl group having 2-8 carbon atoms; R ^c is an alkyl group or phenyl group having 1-8 carbon atoms; R ^d is selected from the group having 1-8 carbon atoms Atomic alkyl group, alkoxy group with 1-8 carbon atoms, and hydroxyl group; there are at least three R ^b in the molecule; in the molecule, at least the total number of R ^b , R ^c and R ^d 50% is an alkyl group having 1-8 carbon atoms; n is 0 or 1; m1 is a number having a value of at least 0; m2 is a number having a value of at least 1; and m1+m2=15-995.

In the aforementioned general formula (5) or the aforementioned general formula (3), within the same molecule, each R ^b may be the same or different, each R ^c may be the same or different, and each R ^d may be the same or different. The order of (R ^b R ^c SiO _2/2 ) units and (R ^c ₂ SiO _2/2 ) units is optional, but when m1 is a number whose value is greater than or equal to 1, in the aforementioned general formula ( 5) or the aforementioned general formula (3) is usually random.

[0021] Here, typical examples of the alkyl group having 1 to 8 carbon atoms are methyl, ethyl, propyl and the like, among which methyl is preferred. Typical examples of the alkenyl group having 2 to 8 carbon atoms are vinyl, allyl, hexenyl and the like, among which vinyl is preferred. The alkoxy group having 1 to 8 carbon atoms may be methoxy, ethoxy and the like.

The R ^b R ^c ₂ SiO _1/2 unit may, for example, be a Vi(Me) ₂ SiO _1/2 unit, a He(Me) ₂ SiO _1/2 unit or a ViMePhSiO _1/2 unit. The R ^d R ^c ₂ SiO _1/2 unit can be exemplified by (Me) ₃ SiO _1/2 unit, (Me) ₂ PhSiO _1/2 unit, (HO)(Me) ₂ SiO _1/2 unit and (MeO)( Me) ₂ SiO _1/2 unit. Combinations of these units (eg Vi(Me ₂ )SiO _1/2 units and (Me) ₃ SiO _1/2 units) are possible within the same molecule.

The R ^b R ^c SiO _2/2 unit may, for example, be a ViMeSiO _2/2 unit. The R ^c ₂ SiO _2/2 unit may, for example, be a (Me) ₂ SiO _2/2 unit or a MePhSiO _2/2 unit. Combinations of these units are also possible within the same molecule.

[0022] The silicon-bonded alkenyl groups in component (A) undergo crosslinking through a hydrosilylation reaction with the silicon-bonded hydrogen atoms in component (C). Therefore at least two alkenyl groups must be present in each molecule; at least three alkenyl groups must be present in each molecule in order to produce good adhesion to substrates in sheet form; and preferably the alkenyl groups are present in Within at least 4 terminal siloxane units.

Component (A) is an essential component of the solventless cured coating-forming organopolysiloxane composition of the present invention. Since it has a branched structure and a low degree of polymerization, it shows low compatibility with component (B) which has a linear structure and has a high viscosity and thus a high degree of polymerization. As a result, efficient migration of the component (B) to the surface of the cured coating layer formed by the hydrosilylation reaction can be induced. Due to this, incorporation of only a small amount of component (B) can provide a cured coating with excellent slipperiness.

[0023] From the viewpoint of coatability on substrates in sheet form and properties of cured coatings, the viscosity of component (A) under consideration at 25° C. is from 10 to 1000 mPa.s, and preferably at 25 The viscosity at ℃ is 20-500mPa.s.

Branched structure-containing organopolysiloxanes represented by the following average siloxane unit formulas are specific examples described below.

(1): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) ₂ ((CH ₃ ) ₂ SiO) ₅₄ (SiO _4/2 )

(2): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _1.8 ((CH ₃ ) ₂ SiO) ₁₀₃ (SiO _4/2 )

(3): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _21.9 ((CH ₃ ) ₂ SiO) ₁₃₆ (SiO _4/2 )

(4): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _18.2 ((CH ₃ ) ₂ SiO) ₁₈₅ (SiO _4/2 )

(5): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _8.2 ((CH ₃ ) ₂ SiO) ₂₁₀ (SiO _4/2 )

(6): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _43.5 ((CH ₃ ) ₂ SiO) ₂₄₂ (SiO _4/2 )

(7): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ ((CH ₃ ) ₂ SiO) ₅₆ (SiO _4/2 )

(8): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ ((CH ₃ ) ₂ SiO) ₁₅₀ (SiO _4/2 )

(9): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₂ ((CH ₃ ) ₃ SiO _1/2 ) ₂ (Vi(CH ₃ )SiO _2/2 ) ₂ ((CH ₃ ) ₂ SiO) ₅₄ (SiO _4/2 )

(10): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₃ ((CH ₃ ) ₃ SiO _1/2 )((CH ₃ ) ₂ SiO) ₁₅₀ (SiO _4/2 )

A plurality of components (A) different from each other can also be used together to prepare the same composition.

[0024] Table 1 shows the viscosities and coefficients thereof for the aforementioned siloxane unit formula (3) of the branched structure-containing organopolysiloxanes listed above.

Table 1

(4n+m1) (m1+m2) Viscosity (mPa.s) (1) 6 56 46 (2) 5.8 104.8 122 (3) 25.9 157.9 111 (4) 22.2 203.2 235 (5) 12.2 218.2 366 (6) 47.5 285.5 375 (7) 4 56 47 (8) 4 180 160

[0025] This component (A) can be produced by the production methods described in Reference Patent Document 8 and Reference Patent Document 9. For example, by introducing a predetermined amount of [Vi(Me) ₂ SiO _1/2 ] ₄ SiO _4/2 and octamethylcyclotetrasiloxane and/or tetramethyltetravinylcyclotetrasiloxane and a catalytic amount of Trifluoromethanesulfonic acid is added to the reaction vessel and stirred at 80-90° C. for several hours, followed by neutralization of the catalyst residue, filtration, and removal of low boiling point compounds from the filtrate, thereby proceeding to the production of component (A).

The average siloxane unit formula in the product can be determined by the incorporation ratio of the starting siloxane, NMR analysis, analysis to determine the vinyl content, and the like.

Component (B) plays the role of improving the strippability of the cured coating to sticky substances and also provides the sliding property of the cured coating, and the component (B) is represented by the average structural formula (1) Diorganopolysiloxanes having a viscosity of at least 100,000 mPa.s at 25°C:

R ^a R ^c ₂ SiO(R ^b R ^c SiO _2/2 ) _n1 (R ^c ₂ SiO _2/2 ) _n2 SiR ^c ₂ R ^a (1)

(Wherein R ^a is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, a phenyl group, an alkoxy group having 1-8 carbon atoms, and a hydroxyl group ; R ^b is an alkenyl group having 2-8 carbon atoms; R ^c is an alkyl group or phenyl group having 1-8 carbon atoms; 0- of the total number of R ^a , R ^b and R ^c in the molecule 0.1% is an alkenyl group having 2-8 carbon atoms; at least 50% of the total number of Ra ^{, Rb} and ^Rc in the molecule is an alkyl group having 1-8 carbon atoms; n1 is a value of at least 0 n2 is a number having a value of at least 1; and n1+n2 is a number providing a viscosity of this component at 25° C. of at least 100,000 mPa.s). Component (B) gradually rises to the coating formed when curing occurs through the hydrosilylation reaction between components (A) and (C), and thereby imparts excellent slipperiness to the surface of the cured coating.

In the aforementioned general formula (1), within the same molecule, each R ^a may be the same or different, each R ^b may be the same or different, and each R ^c may be the same or different.

[0027] Here, typical examples of the alkyl group having 1 to 8 carbon atoms are methyl, ethyl, propyl and the like, among which methyl is preferred. Typical examples of the alkenyl group having 2 to 8 carbon atoms are vinyl, allyl and hexenyl, among which vinyl is preferred. The alkoxy group having 1 to 8 carbon atoms may be, for example, methoxy, ethoxy and the like.

The R ^a R ^c ₂ SiO _1/2 unit may, for example, be a Vi(Me) ₂ SiO _1/2 unit, a He(Me) ₂ SiO _1/2 unit, a ViMePhSiO _1/2 unit, or a (Me) ₃ SiO _1/2 unit , (Me) ₂ PhSiO _1/2 unit, (HO)(Me) ₂ SiO _1/2 unit and (MeO)(Me) ₂ SiO _1/2 unit.

The R ^b R ^c SiO _2/2 unit may, for example, be a ViMeSiO _2/2 unit.

The R ^c ₂ SiO _2/2 unit may, for example, be a (Me) ₂ SiO _2/2 unit or a MePhSiO _2/2 unit.

Combinations of these units are possible within the same molecule.

[0028] Component (B) includes a component having a silicon-bonded alkenyl group in the molecule and thus capable of undergoing a hydrosilylation reaction with component (C); having a silicon-bonded hydroxy groups (silanol groups) and thus capable of undergoing a condensation reaction with component (C); and components which contain neither alkenyl nor silanol groups and are therefore non-reactive. From the standpoint of residual adhesiveness associated with cured coatings, component (B) having an alkenyl group in the molecule and thus capable of undergoing a hydrosilylation reaction with component (C) is preferred, and secondarily at the end of the molecular chain Component (B) that has a silicon-bonded hydroxyl group (silanol group) in position and is therefore capable of undergoing a condensation reaction with component (C).

With respect to component (B) having silicon-bonded alkenyl groups in the molecule and thus capable of undergoing a hydrosilylation reaction with component (C), an excessively high alkenyl group content leads to impaired release properties, And lead to a decrease in the slipperiness of the cured coating, and thus this content is 0 (not including 0) to 0.1 mol% of the silicon-bonded organic groups in the molecule. The silicon-bonded alkenyl group may be present only at the terminal position of the molecular chain, only at the side chain position, or both at the terminal position and at the side chain position. The component (B) containing a silicon-bonded hydroxyl group (silanol group) at the terminal position of the molecular chain may also have an alkenyl group at the side chain position. The alkenyl content is 0 (not including 0) to 0.1 mol% of the silicon-bonded organic groups in the molecule.

[0030] The viscosity of component (B) at 25° C. is at least 100,000 mPa.s, and from the viewpoint of residual adhesiveness, its viscosity is preferably at least 1,000,000 mPa.s, and component (B) is more preferably at least Compound at ambient temperature. When component (B) is in the form of a gum, it has measurable plasticity and at the same time is visibly solid, and when its mass is allowed to stand, it gradually decreases in height and spreads out into the surrounding area.

[0031] Component (B) can be specifically exemplified by dimethyl polysiloxane, dimethyl siloxane methyl octyl siloxane copolymer, dimethyl siloxane methyl vinyl silicon Oxane copolymer, dimethylsiloxane-methylhexenylsiloxane copolymer, dimethylsiloxane-methylphenylsiloxane copolymer, and dimethylsiloxane-diphenyl siloxane copolymers, in each case having dimethylvinylsiloxy, dimethylallylsiloxy, dimethylhexenylsiloxy at the end of the molecular chain group, dimethylhydroxysiloxy, trimethylsiloxy or dimethylphenylsiloxy.

Polysiloxanes having different end groups or different side chains or different end groups and different side chains can also be used together to prepare the same composition.

[0032] In each case, 0.5 to 15 parts by weight and preferably 1.0 to 8 parts by weight of component (B) are incorporated, based on 100 parts by weight of the aforementioned component (A). When the component (B) is incorporated in an amount smaller than the aforementioned lower limit, the surface of the cured coating has insufficient slipperiness. When the aforementioned upper limit is exceeded, the organopolysiloxane composition has an excessively high viscosity, thereby causing breakage of the thin film coating on the sheet-form substrate.

[0033] Component (C) is an alkyl or phenyl group having a viscosity of 1-1000 mPa.s at 25° C. and having at least two silicon-bonded hydrogen atoms and 1-8 carbon atoms per molecule as An organohydrogenpolysiloxane of silicon-bonded organic groups that acts as a crosslinker for component (A). Crosslinking occurs by a hydrosilylation reaction between the silicon-bonded hydrogen atoms in this component and the silicon-bonded alkenyl groups in component (A). When component (B) contains silicon-bonded alkenyl groups, the silicon-bonded alkenyl groups in component (B) also participate in the hydrosilylation reaction. As a result, there must be at least two silicon-bonded hydrogen atoms per molecule, and preferably at least three silicon-bonded hydrogen atoms per molecule.

[0034] The bonding position of the silicon-bonded hydrogen atoms is not particularly limited, and for example, they may be bonded at the terminal position of the molecular chain, at the side chain position, or at both positions.

The content of silicon-bonded hydrogen atoms is preferably 0.1 to 20 wt%, and more preferably 0.5 to 18 wt%.

[0035] Silicon-bonded organic groups include phenyl and alkyl groups with 1-8 carbon atoms, such as methyl, ethyl, propyl, butyl, octyl, etc., preferably the total number of these organic groups At least 50% are alkyl groups having 1-8 carbon atoms. Among these alkyl groups, a methyl group is preferred from the viewpoints of cured coating properties and ease of production. The molecular structure of component (C) is exemplified by linear, branched and cyclic.

[0036] Component (C) has a viscosity at 25°C of 1-1000 mPa.s, and preferably 5-500 mPa.s. The basis is as follows: when the viscosity at 25° C. is less than 1 mPa.s, component (C) is easy to volatilize the organopolysiloxane composition, and the organopolysiloxane composition needs to be above 1000 mPa.s Takes long curing time.

[0037] This component (C) can be exemplified by trimethylsiloxy-terminated methylhydrogenpolysiloxane, trimethylsiloxy-terminated dimethylsiloxane.methylhydrogensiloxane Oxane copolymer, dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer, cyclic methylhydrogenpolysiloxane, cyclic methylhydrogenpolysiloxane • Dimethylsiloxane copolymers, tris(dimethylhydrogensiloxy)methylsilane and tetrakis(dimethylhydrogensiloxy)silane.

A plurality of components (C) different from each other may be used together to prepare the same composition.

[0038] Component (C) is incorporated in an amount sufficient to provide a ratio of 0.8:1 to 5:1 of silicon-bonded hydrogen atoms within component (C) to components (A) and (B) internal chains The molar ratio, and preferably the amount, of alkenyl groups is sufficient to provide this molar ratio in the range of 0.9:1 to 3:1.

When this molar ratio is less than the above-mentioned lower limit, curability decreases, and when it exceeds the above-mentioned upper limit, great peeling resistance occurs and practical peelability cannot be obtained.

[0039] Component (D) is to promote the hydrosilylation reaction between the silicon-bonded hydrogen atoms in component (C) and the silicon-bonded alkenyl groups in component (A) and act to pass through the composition The addition reaction between components (A) and (C) causes crosslinking of the catalyst. This catalyst also promotes hydrosilylation with silicon-bonded alkenyl groups in component (B) when component (B) contains one or more silicon-bonded alkenyl groups per molecule reaction.

There is no particular limitation on this component (D) except that it is a catalyst used for the hydrosilylation reaction, and component (D) can be specifically exemplified by platinum-based catalysts such as chloroplatinic acid, alcohol-modified chlorine Platinic acid, chloroplatinic acid/olefin complex, chloroplatinic acid/ketone complex, platinum/alkenyl siloxane complex, platinum tetrachloride, platinum micropowder, supported on a carrier such as alumina powder or di Solid platinum on silica powder, platinum black, platinum olefin complexes, platinum carbonyl complexes, and powdery thermoplastic resins (such as methyl methacrylate resin, poly Carbonate resin, polystyrene resin, silicone resin, etc.).

Other examples are rhodium catalysts such as [Rh(O ₂ CCH ₃ ) ₂ ] ₂ , Rh(O ₂ CCH ₃ ) ₃ , Rh ₂ (C ₈ H ₁₅ O ₂ ) ₄ , Rh(C ₅ H ₇ O ₂ ) ₃ , Rh(C ₅ H ₇ O ₂ )(CO) ₂ , Rh(CO)[Ph ₃ P](C ₅ H ₇ O ₂ ), RhX ₃ [(R ⁶ ) ₂ S] ₃ , (R ⁷ ₃ P) ₂ (CO)X, (R ⁷ ₃ P) ₂ Rh(CO)H, Rh ₂ X ₂ Y ₄ , H _a Rh _b (E) _c Cl _d and Rh[O(CO)R ₃ ] _3-n (OH) _n (in these formulas, X is a hydrogen atom, a chlorine atom, a bromine atom or an iodine atom; Y is an alkyl group, CO or C ₈ H ₁₄ ; R ⁶ is an alkyl group, a cycloalkyl group or an aryl group ^R is an alkyl, aryl, alkoxy or aryloxy group; E is an alkene; a is 0 or 1; b is 1 or 2; c is an integer of 1-4; d is 2, 3 or 4 ; and n is 0 or 1), and iridium catalysts such as Ir(OOCCH ₃ ) ₃ , Ir(C ₅ H ₇ O ₂ ) ₃ , [Ir(Z)(E) ₂ ] ₂ and [Ir(Z)( Dien)] ₂ (In these formulas, Z is a chlorine atom, a bromine atom, an iodine atom or an alkoxy group; E is an alkene, and Dien is a cyclooctadiene).

From the viewpoint of the ability to accelerate the reaction, preferred chloroplatinic acid, platinum/vinylsiloxane complexes, and platinum olefin complexes, and particularly preferred chloroplatinic acid/divinyltetramethyldisilazine Oxane complexes, chloroplatinic acid/tetramethyltetravinylcyclotetrasiloxane complexes, and platinum/alkenylsiloxane complexes such as platinum divinyltetramethyldisiloxane complex, platinum/tetramethyltetravinylcyclotetrasiloxane complex, etc.

[0042] In each case, based on the total weight of the solvent-free cured release coating-forming organopolysiloxane composition of the present invention, based on the amount of metal in component (D), incorporated Catalytic amount of component (D), and generally 1-1000 ppm, and preferably 5-500 ppm of component (D) are incorporated.

[0043] In addition to the aforementioned components, the solvent-free cured release coating-forming organopolysiloxane composition of the present invention preferably further contains a hydrosilylation reaction inhibitor (E) so that it is thermally Cures while improving storage stability by inhibiting gelation and curing at ambient temperatures. This hydrosilylation reaction inhibitor can be exemplified by acetylenic compounds, ene-yne compounds, organic nitrogen compounds, organic phosphorus compounds, and oxime compounds, and specifically can be exemplified by acetylenic alcohols such as 3-methyl-1-butane Alkyne-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, phenylbutynol, etc.; and 3-methyl-3-ol -penten-1-yne, 3,5-dimethyl-1-hexyn-3-ene, benzotriazole, 1-ethynyl-1-cyclohexanol and methylvinylcyclosiloxane. In each case, the hydrosilylation reaction inhibitor is usually incorporated in an amount in the range of 0.001 to 5 parts by weight, and preferably in the range of 0.01 to 2 parts by weight, based on 100 parts by weight of component (A), and may Depending on the type of hydrosilylation inhibitor, the properties and amount of the hydrosilylation catalyst incorporated, the amount of alkenyl groups in component (A), and the silicon-bonded hydrogen in component (C) The amount of atoms used to choose.

[0044] The compositions of the present invention comprise components (A)-(D) and additionally on an optional basis component (E), but may also incorporate a vinyl functional organopolysiloxane resin so that Reduces the peel force of cured coatings against adhesive substances. Thickeners, such as micronized silica, may also be incorporated to increase the viscosity of the coating fluid. Known additives such as heat stabilizers, dyes, pigments, etc. may also be incorporated as long as the objects and effects of the present invention are not impaired. Based on the coatability of the composition on a substrate in sheet form, the composition of the invention as a whole preferably has a viscosity in the range of 50-2000 mPa.s at 25°C.

[0045] The compositions of the present invention may be prepared by mixing the foregoing components (A)-(D) or the foregoing components (A)-(E) or these components with any other optional components to homogeneity. The order of incorporation of the components is not particularly limited, however, when the composition is not used immediately after mixing, the mixture of components (A), (B) and (C) is preferably stored separately from component (D), and The two are preferably mixed just before use. In the case of compositions containing components (A)-(E), it is also preferred that the composition obtained by selecting the type of component (E) and adjusting the amount of component (E) incorporated does not experience Cross-linking, undergoes cross-linking and cures when heat is applied.

[0046] It can be obtained by using any of various sheet-form substrates such as cellophane, cardboard, clay-coated paper, polyolefin-laminated paper and especially polyethylene-laminated paper, thermoplastic resin films (e.g., polyester films) , polyethylene film, polypropylene film, polyamide film), natural fiber fabrics, synthetic fiber fabrics, metal foil (for example, aluminum foil) etc., uniformly coat the solvent-free forming and curing anti-corrosion film of the present invention described above. Organopolysiloxane composition of an adhesive coating, and at a temperature suitable for causing components (A) and (C) or components (A), (B) and (C) to undergo crosslinking by hydrosilylation reaction Heating under the condition of , forms a cured coating exhibiting excellent slippage and suitable peeling resistance value with respect to sticky substances on the surface of a substrate in the form of a sheet.

[0047] Generally, 50-200° C. is suitable for the curing temperature of the solvent-free organopolysiloxane composition of the present invention forming a cured release coating on a substrate in sheet form, but When the substrate has good heat resistance, a curing temperature above 200°C can be used. The heating method is not particularly limited, and heating in a hot air circulating oven, passing through a long oven, or irradiating heating using an infrared lamp or a halogen lamp may be exemplified. Curing may also be effected by the use of heat in combination with exposure to ultraviolet radiation. When component (D) is a platinum/alkenyl siloxane complex catalyst, even when based on the total amount of the composition, this catalyst is incorporated in an amount of 50-200 ppm in terms of the amount of platinum metal , can be easily obtained at 100-150°C in a short period of time, that is, 40-1 second, which exhibits excellent adhesion to substrates in sheet form and exhibits excellent peeling properties with respect to sticky substances Cured coating.

[0048] There is no particular limitation on the coating machine used to apply the solvent-free, cured release coating-forming organopolysiloxane composition of the present invention on the surface of a substrate in the form of a sheet, and the coating machine may be, for example, Examples include roll coaters, gravure coaters, air coaters, curtain flow coaters and offset transfer roll coaters. Regarding the tacky substance, the tacky substance can be applied to a release sheet obtained by applying and curing the solvent-free cured release coating-forming organopolysiloxane composition of the present invention on the surface of a substrate in sheet form or On the film, this adhesive substance can be, for example, any of various pressure-sensitive adhesives and various adhesives, examples of which are acrylic resin pressure-sensitive adhesives, rubber-type pressure-sensitive adhesives, and silicone types of pressure sensitive adhesives, as well as acrylic resin adhesives, synthetic rubber type pressure sensitive adhesives, silicone type adhesives, epoxy resin type adhesives, and polyurethane type adhesives agent. Other examples are asphalt, viscous food products such as mochi (ie rice cakes), glues and pastes, and birdlime.

[0049] The compositions of the present invention are useful for forming cured coatings which exhibit good surface slip and good release properties to sticky substances and are especially well suited for use as craft papers, bituminous packaging papers and Reagent for forming cured release coatings for various plastic films. In addition, substrates in sheet form with a release coating formed by curing the composition according to the invention are very suitable, inter alia, for sticky and tacky substances, pressure-sensitive adhesive tapes, pressure-sensitive adhesive labels Use in craft paper, wrapping or wrapping paper, etc.

Example

[0050] Examples and comparative examples are given below in order to specifically describe the present invention; however, the present invention is not limited to the following examples. In the examples and comparative examples that follow, parts are in each case parts by weight, and ppm in each case means ppm by weight. Viscosity and plasticity were measured at 25°C by the methods described below. In addition, cured coatings obtained from solvent-free cured release coating-forming organopolysiloxane compositions were evaluated by measuring the dynamic friction coefficient and peel resistance value at 25°C, respectively, using the methods described below Sliding and peeling properties for sticky substances.

Viscosity and plasticity

Using a digitally displayed viscometer (Vismetron model VDA2 from Shibaura Systems Co., Ltd.), at a spindle rotation speed of 30 rpm, with #2 spindle installed, organopolysiloxane and free The viscosity of the solvent for the cured release coating-forming organopolysiloxane composition.

According to JIS K 6249:2003, Section 8 (plasticity testing) of "Test Method for uncured and cured silicone rubber", use a parallel plate plasticity device to measure the plasticity of organopolysiloxane rubber.

Anti-stripping value

Using a printable tester (model RI-2 obtained from Akira Seisakusho Co., Ltd.), on the surface of polyethylene-laminated paper or cellophane to provide 1.0 g/m ² (in terms of siloxane) A solvent-free, cured release coating-forming organopolysiloxane composition was coated with a dose, followed by heating at 120° C. for 30 seconds in a hot air circulating oven to form a cured coating. Using an applicator, a ^solvent -based acrylic pressure-sensitive adhesive (trade name: Oribain BPS-5127, available from ToyoInk Mfg. Co. ., Ltd.), and heated at 70°C for 2 minutes. Then, fine paper (weight = 64 g/m ² ) was pasted on this acrylic pressure-sensitive adhesive, and the resulting paper laminate was cut into a width of 5 cm to obtain samples. This sample was kept in air for 20 hours at a humidity of 60% and a temperature of 25°C. Then, using a tensile tester, pull the high-grade paper and polyethylene-laminated paper or cellophane at an angle of 180 degrees in the opposite direction at a peeling speed of 0.3m/min, and measure the force required for peeling (N). Samples were then prepared by cutting the paper laminate obtained as described above into a width of 2.5 cm, and under the conditions described above, the measurement of the force (N) required for peeling was performed except that the peeling speed was 100 m /min.

Dynamic coefficient of friction

Using the same conditions as described above for measuring peel resistance, two cured coatings were formed. These cured coatings were then stacked in such a way that the sides of the cured coatings were in contact with each other, followed by pulling using a high-speed peel tester using the conditions of load = 200 g and pulling speed = 5 m/min, and the force required to pull was measured ( g). The force required to pull/200 (g) represents the dynamic coefficient of friction of the cured coating.

[0054] Residual Adhesion

Lumilar 31B polyester tape (product of Nitto Denko Corporation) was bonded to the surface of the cured coating of the sample, followed by aging at 70° C. for 20 hours under an applied load of 20 g/cm ² . Then peel off the tape and stick it on the stainless steel sample. Then, this tape was peeled off at an angle of 180 degrees with respect to the surface of the stainless steel test piece at a peeling speed of 300 mm/min, and the force (g) required for peeling was measured.

In addition, Lumilar 31B polyester tape (product of Nitto Denko Corporation) was similarly pasted on the polytetrafluoroethylene sheet, followed by aging at 70° C. for 20 hours under an applied load of 20 g/cm ² . Then peel off the tape and stick it on the stainless steel sample. Then, this tape was peeled off at an angle of 180 degrees with respect to the surface of the stainless steel test piece at a peeling speed of 300 mm/min, and the force (g) required for peeling was measured.

Using the value of sticking on the polytetrafluoroethylene sheet as 100, the force required when the tape has been stuck to the surface of the cured coating is expressed as a percentage, and this percentage represents the residual adhesion.

[0055] In Examples, a branched structure-containing methylvinylpolysiloxane represented by the following average siloxane unit formula was used as component (A). Vi stands for vinyl.

(1): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) ₂ ((CH ₃ ) ₂ SiO) ₅₄ (SiO _4/2 )

(2): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _1.8 ((CH ₃ ) ₂ SiO) ₁₀₃ (SiO _4/2 )

(3): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _21.9 ((CH ₃ ) ₂ SiO) ₁₃₆ (SiO _4/2 )

(4): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _18.2 ((CH ₃ ) ₂ SiO) ₁₈₅ (SiO _4/2 )

(5): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _8.2 ((CH ₃ ) ₂ SiO) ₂₁₀ (SiO _4/2 )

(6): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _43.5 ((CH ₃ ) ₂ SiO) ₂₄₂ (SiO _4/2 )

(7): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ ((CH ₃ ) ₂ SiO) ₅₆ (SiO _4/2 )

(8): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ ((CH ₃ ) ₂ SiO) ₁₅₀ (SiO _4/2 )

Synthetic example 1

Synthesis (1): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) ₂ ((CH ₃ ) ₂ SiO) ₅₄ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6g), tetramethyltetravinylcyclotetrasiloxane (8.60g), octamethylcyclotetrasiloxane (200g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 46 mPa.s, and its vinyl content was 3.5% by weight.

Synthetic example 2

Synthesis (2): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _1.8 ((CH ₃ ) ₂ SiO) ₁₀₃ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6g), tetramethyltetravinylcyclotetrasiloxane (7.74g), octamethylcyclotetrasiloxane (381g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 122 mPa.s, and its vinyl content was 1.9% by weight.

Synthetic example 3

Synthesis (3): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _21.9 ((CH ₃ ) ₂ SiO) ₁₃₆ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO ₄ /2 (21.6g), tetramethyltetravinylcyclotetrasiloxane (94.2g), octamethylcyclotetrasiloxane (503g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 111 mPa.s, and its vinyl content was 5.6% by weight.

Synthetic example 4

Synthesis (4): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _18.2 ((CH ₃ ) ₂ SiO) ₁₈₅ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6g), tetramethyltetravinylcyclotetrasiloxane (78.3g), octamethylcyclotetrasiloxane (685g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 235 mPa.s, and its vinyl content was 3.8% by weight.

Synthetic example 5

Synthesis (5): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _8.2 ((CH ₃ ) ₂ SiO) ₂₁₀ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6g), tetramethyltetravinylcyclotetrasiloxane (35.3g), octamethylcyclotetrasiloxane (777g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 366 mPa.s, and its vinyl content was 2.0% by weight.

Synthetic example 6

Synthesis (6): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ (Vi(CH ₃ )SiO _2/2 ) _43.5 ((CH ₃ ) ₂ SiO) ₂₄₂ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6g), tetramethyltetravinylcyclotetrasiloxane (187g), octamethylcyclotetrasiloxane (895g) and Trifluoromethanesulfonic acid (1.2 g) was introduced into the reaction vessel and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 375 mPa.s, and its vinyl content was 5.8% by weight.

Synthetic example 7

Synthesis (7): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ ((CH ₃ ) ₂ SiO) ₅₆ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6 g), octamethylcyclotetrasiloxane (207 g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 47 mPa.s, and its vinyl content was 2.4% by weight.

Synthetic example 8

Synthesis (8): (Vi(CH ₃ ) ₂ SiO _1/2 ) ₄ ((CH ₃ ) ₂ SiO) ₁₅₀ (SiO _4/2 )

[Vi(CH ₃ ) ₂ SiO _1/2 ] ₄ SiO _4/2 (21.6 g), octamethylcyclotetrasiloxane (555 g) and trifluoromethanesulfonic acid (1.2 g) were introduced into the reaction vessel, and stirred at a temperature of 80-90° C. for 6 hours. The resulting reaction mixture was then cooled to room temperature. Calcium carbonate powder (1.0 g) was added to the cooled reaction mixture, followed by stirring for 3 hours and filtering. The filtrate was stripped for 2 hours at a pressure of 40 mbar (4000 Pa) and a temperature of about 150°C. The viscosity of the stripped residue was 160 mPa.s, and its vinyl content was 0.90% by weight.

Embodiment 1

Mix 100 parts of (A) methyl vinyl polysiloxane (viscosity = 46 mPa.s) containing branched structure represented by the average siloxane unit formula (1) given above, 3.0 parts of (B) molecular Dimethyl polysiloxane compound (vinyl content=0.02 wt%, 7.4× ^10-4 mol%; plasticity=140) terminated with dimethylvinylsiloxy groups at both ends, 6.6 parts ( C) Methylhydropolysiloxane (viscosity = 25 mPa.s, silicon-bonded hydrogen content = 1.6 wt %) capped with trimethylsiloxy groups at both ends of the molecule (silicon-bonded hydrogen atoms /vinyl molar ratio = 1.3) and 0.30 parts of (E) 1-ethynyl-1-cyclohexanol to homogeneity. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used is sufficient to obtain 100 ppm platinum metal to obtain a solvent-free organopolysiloxane composition (viscosity = 90 mPa.s) forming a cured release coating. Dynamic coefficient of friction and anti-peeling values were measured on cured coatings obtained by curing this organopolysiloxane composition on polyethylene-laminated paper; the results are shown in Table 4.

Embodiment 2-7

Mix 100 parts of (A) with the methyl group containing branched structure represented by the average siloxane unit formula (2), (3), (4), (5), (6) or (7) given above Vinyl polysiloxane, 3.0 parts of (B) dimethyl polysiloxane compound (vinyl content = 0.02 wt%, 7.4×10 ^{- 4} mol%; plasticity = 140), (C) methylhydrogen polysiloxane (viscosity = 25 mPa.s, silicon-bonded hydrogen content = 1.6 wt%) (parts sufficient to give a silicon-bonded hydrogen atom/vinyl molar ratio of 1.3), and 0.30 parts of (E) 1-ethynyl-1-cyclohexanol to homogeneity. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used was sufficient to obtain 100 ppm platinum metal to obtain a solvent-free cured release coating-forming organopolysiloxane composition having a viscosity as shown in Table 2. Dynamic coefficients of friction and anti-peeling values were measured on cured coatings obtained by curing these organopolysiloxane compositions on polyethylene-laminated paper; the results are shown in Table 4.

Embodiment 8

The measurements were carried out under the same conditions as in Example 7, but in this case cellophane was used as the substrate in sheet form instead of polyethylene-laminated paper; the results are shown in Table 4.

Table 2

Embodiment 9

Mix 100 parts of (A) methyl vinyl polysiloxane (viscosity = 46 mPa.s) containing branched structure represented by the average siloxane unit formula (1) given above, 3.0 parts of (B) molecular Dimethyl polysiloxane compound (plasticity = 140) with trimethylsiloxy terminated at both ends, 6.6 parts of (C) methyl polysiloxane with trimethylsiloxy terminated at both ends Hydrogen polysiloxane (viscosity = 25 mPa.s, silicon-bonded hydrogen content = 1.6 wt%) and 0.30 parts of (E) 1-ethynyl-1-cyclohexanol to homogeneity. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used was sufficient to obtain 100 ppm platinum metal to obtain a solvent-free cured release coating-forming organopolysiloxane composition having a viscosity as shown in Table 2. The dynamic coefficient of friction and the resistance to peeling were measured on cured coatings obtained by curing this organopolysiloxane composition by the method described previously; these results are shown in Table 4.

Embodiment 10

Mix 100 parts of (A) methyl vinyl polysiloxane (viscosity = 46 mPa.s) containing branched structure represented by the average siloxane unit formula (1) given above, 3.0 parts of (B) molecular A dimethylsiloxane·methylvinylsiloxane copolymer compound (vinyl content=0.063wt%, 2.3×10 ^-3 mol%) endcapped with dimethylvinylsiloxy at both ends; Plasticity = 140), 6.6 parts (C) methylhydrogen polysiloxane (viscosity = 25 mPa.s, silicon-bonded hydrogen content = 1.6 wt %) terminated with trimethylsiloxy at both ends of the molecule ) and 0.30 parts of (E) 1-ethynyl-1-cyclohexanol to homogeneity. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used was sufficient to obtain 100 ppm platinum metal to obtain a solvent-free cured release coating-forming organopolysiloxane composition having a viscosity as shown in Table 3. The dynamic coefficient of friction and the resistance to peeling were measured on cured coatings obtained by curing this organopolysiloxane composition by the method described previously; these results are shown in Table 4.

Embodiment 11

Mix 100 parts of (A) methyl vinyl polysiloxane (viscosity = 46 mPa.s) containing branched structure represented by the average siloxane unit formula (1) given above, 3.0 parts of (B) molecular Dimethyl polysiloxane compound (plasticity = 140) terminated with silanol groups at both ends, 6.6 parts of (C) methyl hydrogen polysiloxane with trimethylsiloxy terminated at both ends Alkane (viscosity = 25 mPa.s, silicon-bonded hydrogen content = 1.6 wt%) and 0.30 parts of (E) 1-ethynyl-1-cyclohexanol to homogeneity. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used was sufficient to obtain 100 ppm platinum metal to obtain a solvent-free cured release coating-forming organopolysiloxane composition having a viscosity as shown in Table 2. The dynamic coefficient of friction and the resistance to peeling were measured on cured coatings obtained by curing this organopolysiloxane composition by the method described previously; these results are shown in Table 4.

table 3

Comparative example 1

Mix 100 parts of dimethylpolysiloxane (viscosity = 60 mPa.s) endcapped with dimethylvinylsiloxy groups represented by the following average structural formula:

3.0 parts of (B) dimethylpolysiloxane rubber compound (vinyl content=0.02wt%, 7.4× ^10-4 mol%; plasticity= 140), 4.8 parts of (C) methylhydropolysiloxane (viscosity = 20 mPa.s, silicon-bonded hydrogen content = 1.6 wt %) and 0.30 Part (E) 1-ethynyl-1-cyclohexanol until uniform. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used is sufficient to obtain 100 ppm platinum metal to obtain a solvent-free organopolysiloxane composition (viscosity = 250 mPa.s) forming a cured release coating. Dynamic friction coefficient and peel resistance values were measured on the resulting compositions; these results are shown in Table 4.

Comparative example 2

Mix 100 parts of a dimethylvinylsiloxy-terminated dimethylvinylsiloxane copolymer (viscosity = 70 mPa.s) represented by the following average structural formula:

3.0 parts of (B) dimethylpolysiloxane rubber compound (vinyl content=0.02wt%, 7.4× ^10-4 mol%; plasticity= 140), 8.1 parts of (C) methylhydropolysiloxane (viscosity = 20 mPa.s, silicon-bonded hydrogen content = 1.6 wt %) and 0.30 Part (E) 1-ethynyl-1-cyclohexanol until uniform. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which The amount used is sufficient to obtain 100 ppm platinum metal to obtain a solvent-free organopolysiloxane composition (viscosity = 200 mPa.s) forming a cured release coating. Dynamic friction coefficient and peel resistance values were measured on the resulting compositions; these results are shown in Table 4.

Comparative example 3

Mix 100 parts of dimethylpolysiloxane (viscosity = 400 mPa.s) endcapped with dimethylvinylsiloxy groups represented by the following average structural formula:

1.0 parts (B ¹ ) dimethylsiloxane·diphenylsiloxane copolymer (diphenylsiloxane Unit content = 5wt%, viscosity = 50,000mPa.s), 2.0 parts (C) methylhydropolysiloxane (viscosity = 20mPa.s, silicon bonded Combined hydrogen content = 1.6 wt%) and 0.30 parts of (E) 1-ethynyl-1-cyclohexanol to homogeneity. Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which Amount sufficient to obtain 100 ppm platinum metal to obtain a solvent-free organopolysiloxane composition (viscosity = 400 mPa.s) forming a cured release coating. Dynamic friction coefficient and peel resistance values were measured on the resulting compositions; these results are shown in Table 4.

Comparative example 4

11.3 parts of (C) methylhydropolysiloxane (viscosity = 20 mPa.s, silicon-bonded hydrogen content = 1.6 wt %) and 0.30 parts ( E) 1-ethynyl-1-cyclohexanol is uniformly mixed into 100 parts of (A) the methyl vinyl polysiloxane containing branched structure shown in the aforementioned average siloxane unit formula (4) (viscosity=235mPa .s). Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which Amount sufficient to obtain 100 ppm platinum metal to obtain a solvent-free organopolysiloxane composition (viscosity = 180 mPa.s) forming a cured release coating. Dynamic friction coefficient and peel resistance values were measured on the resulting compositions; these results are shown in Table 4.

Comparative example 5

2.8 parts of (C) methylhydrogen polysiloxane (viscosity = 20 mPa.s, silicon-bonded hydrogen content = 1.6 wt %) and 0.30 parts ( E) 1-ethynyl-1-cyclohexanol is uniformly mixed into 100 parts (A) methyl vinyl polysiloxane containing branched structure shown in the aforementioned average siloxane unit formula (8) (viscosity=160mPa .s). Into this mixture was mixed (D) chloroplatinic acid·1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum metal content = 0.60 wt %), which Amount sufficient to obtain 100 ppm platinum metal to obtain a solvent-free organopolysiloxane composition (viscosity = 150 mPa.s) forming a cured release coating. Dynamic friction coefficient and peel resistance values were measured on the resulting compositions; these results are shown in Table 4.

Table 4

[0077] The results reported above indicate that the cured coatings of Examples 1-11 have a lower dynamic coefficient of friction and thus better slip than the cured coatings of Comparative Examples 1-5. It is also shown that the cured coatings of Examples 1-11 have smaller peel resistance values during high-speed peeling and thus have better peeling properties to sticky substances than the cured coatings of Comparative Examples 1-3.

[0078] The solvent-free cured release coating-forming organopolysiloxane composition of the present invention can be used to form a cured coating on the surface of a substrate in the form of a sheet that exhibits excellent slidability and excellent release properties to sticky substances. layer. The substrate in the form of a sheet bearing the cured coating obtained from the aforementioned composition of the present invention can be used in craft papers, papers for wrapping or packaging sticky substances, pressure sensitive adhesive tapes, pressure sensitive labels and the like.

Claims (9)

1. A solvent-free organopolysiloxane composition forming a cured release coating, characterized in that it comprises: (A) 100 parts by weight have a branched structure and a viscosity of 10-1,000 mPa.s at 25°C, comprising siloxane units (i)-(iii) described below, and having a plurality of siloxane units The linear part of (ii), and the organopolysiloxane fluid containing the branch point of the siloxane unit (i), wherein the end of the linear part is terminated with the siloxane unit (iii) (i) Siloxane units represented by the chemical formula SiO _4/2 : 1 or more (ii) Siloxane units represented by the general formula R ₂ SiO _2/2 : 15-995 (iii) A siloxane unit represented by the general formula R ^a R ₂ SiO _1/2 In these general formulas, ^Ra is selected from alkyl having 1-8 carbon atoms, alkenyl having 2-8 carbon atoms, phenyl, alkoxy having 1-8 carbon atoms, and A group of hydroxyl, and R is selected from an alkyl group with 1-8 carbon atoms, an alkenyl group with 2-8 carbon atoms, and a phenyl group, wherein at least one of R ^and R in the molecule Three are alkenyl groups having 2-8 carbon atoms, and at least 50% of the total number of R ^and R in the molecule are alkyl groups having 1-8 carbon atoms; (B) 0.5-15 parts by weight of a diorganopolysiloxane represented by the average structural formula (1) and having a viscosity of at least 100,000 mPa.s at 25°C: R ^a R ^c ₂ SiO(R ^b R ^c SiO _2/2 ) _n1 (R ^c ₂ SiO _2/2 ) _n2 SiR ^c ₂ R ^a (1) Wherein R ^a is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, a phenyl group, an alkoxy group having 1-8 carbon atoms, and a hydroxyl group; R ^b is an alkenyl group having 2-8 carbon atoms; R ^c is an alkyl group or phenyl group having 1-8 carbon atoms; 0-0.1 of the total number of R ^a , R ^b and R ^c in the molecule % is an alkenyl group having 2 to 8 carbon atoms; at least 50% of the total number of R ^a , R ^b and R ^c in the molecule is an alkyl group having 1 to 8 carbon atoms; n1 is a value of at least 0 n2 is a number having a value of at least 1; and n1+n2 is a number providing a viscosity of this component at 25°C of at least 100,000 mPa.s; (C) an organohydrogenpolysiloxane having a viscosity of 1 to 1000 mPa.s at 25° C. and having at least two silicon-bonded hydrogen atoms per molecule, wherein the silicon-bonded organic group has 1 - an alkyl group of 8 carbon atoms, or a phenyl group, in an amount sufficient to provide a ratio of 0.8:1 to 5:1 of silicon-bonded hydrogen atoms to component (A ) and (B) the molar ratio of internal alkenyl groups; and (D) A catalytic amount of a hydrosilylation catalyst. 2. The solvent-free organopolysiloxane composition for forming a cured release coating according to claim 1, wherein component (A) has a branched structure and is represented by the following average siloxane unit formula (2) Organopolysiloxane represented by: (R ^a R ₂ SiO _1/2 ) ₄ (R ₂ SiO _2/2 ) _m (SiO _4/2 ) (2) Wherein R ^a is selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, a phenyl group, an alkoxy group having 1-8 carbon atoms, and a hydroxyl group; R is a group selected from an alkyl group having 1-8 carbon atoms, an alkenyl group having 2-8 carbon atoms, and a phenyl group; at least 3 of R ^and R in the molecule are 2 - an alkenyl group with 8 carbon atoms; at least 50% of the total number of R ^a and R in the molecule is an alkyl group with 1-8 carbon atoms; and m = 15-995. 3. The solvent-free organopolysiloxane composition for forming a cured release coating according to claim 2, characterized in that component (A) has a branched structure and is represented by the following average siloxane unit formula (3) Organopolysiloxane represented by: [(R ^b R ^c ₂ SiO _1/2 ) _n (R ^d R ^c ₂ SiO _1/2 ) _1-n ] ₄ (R ^b R ^c SiO _2/2 ) _m1 (R ^c ₂ SiO _2/2 ) _m2 (SiO _4/2 )(3) Wherein R ^b is an alkenyl group with 2-8 carbon atoms; R ^c is an alkyl group or phenyl group with 1-8 carbon atoms; R ^d is selected from an alkyl group with 1-8 carbon atoms, Alkoxy, and hydroxyl radicals having 1 to 8 carbon atoms; in the molecule at least three R ^b ; in the molecule at least 50% of the total number of R ^b , R ^c and R ^d are 1 - an alkyl group of 8 carbon atoms; n is 0 or 1; m1 is a number having a value of at least 0; m2 is a number having a value of at least 1; and m1+m2=15-995. 4. The solvent-free organopolysiloxane composition for forming a cured release coating according to claim 2, characterized in that, in the average siloxane unit formula (2), R is a methyl group, and R ^a is vinyl; in the average structural formula (1), R ^a is vinyl, methyl or hydroxyl, R ^b is vinyl, and R ^c is methyl; and the alkyl in component (C) is methyl . 5. The solvent-free organopolysiloxane composition for forming a cured release coating according to claim 3, characterized in that, in the average siloxane unit formula (3), R ^b is a vinyl group, R ^c is methyl, and n=1; in average structural formula (1), R ^a is vinyl, methyl or hydroxyl, R ^b is vinyl, and R ^c is methyl; in component (C) alkyl is methyl. 6. The solvent-free, cured release coating-forming organopolysiloxane composition according to any one of claims 1 to 3, characterized in that the composition as a whole has a viscosity at 25° C. of 50 to 2000 mPa .s. 7. The solvent-free organopolysiloxane composition for forming a cured release coating according to any one of claims 1-3, characterized in that, it additionally comprises (E) 0.001-5 parts by weight of hydrosilylation reaction Inhibitor, and it does not cure at ambient temperature but cures when heat is applied. 8. A cured release coating obtained by curing a solvent-free, cured release coating-forming organopolysiloxane composition according to any one of claims 1-7 in film form on a substrate in sheet form Coated substrates in sheet form. 9. Substrate in sheet form with cured release coating according to claim 8, characterized in that the substrate in sheet form is cellophane, clay-coated paper, polyolefin-laminated paper, thermoplastic resin film or metal foil.